Buy a little bit of bitcoin every week don't care if it's a $1, $5, $10, $100, figure out what you can afford every week and buy it, get rid of unnecessary expenses or whatever you can think of getting rid of and spend it on bitcoin
5 to 10 years if you buy some every week you will be a multi millionaire
The method you wrote is called Dollar Cost Averaging (DCA). That's one of the most effective strategy if anyone wants to profit in crypto (in my opinion). We just buy a certain for a certain period of time and keep on buying until we see an opportunity to profit from it. But one should bear in mind that this method is a long term method. So whoever thinks of using DCA should be ready to buy and hold for a long time.